Conventionally, a stopper for keyboard-based musical instruments of this type is known, for example, from Patent Document 1. This stopper is used in an upright piano which is equipped with a silence function, where the stopper is arranged between a string and a hammer and attached along a pivotal shaft which extends in a direction in which keys are arranged side by side. This pivotal shaft is attached to a piano case. The stopper is composed of a hard cushion, a soft cushion, and an extremely soft cushion, which are laminated one on another, arranged in this order from the pivotal shaft. The hammer is configured to pivotally move toward a string through a wippen and a jack which pivotally move to the accompaniment of a key touch.
With the foregoing configuration, when a silent play is performed, the pivotal shaft is rotated to place the extremely soft cushion of the stopper in opposition to the hammer. As the key is touched in this state, the hammer comes into contact with the extremely soft cushion of the stopper when it arrives at a predetermined pivotal angle before the jack comes off. Thus hammer thus brought into contact with the extremely soft cushion compresses the extremely soft, soft, and hard cushions, while it is braked by them, thereby preventing the hammer from striking the string. Also, collision noise generated when the hammer comes into contact with the stopper is reduced by the cushions.
However, since the conventional stopper is composed of three, i.e., extremely soft, soft, and hard cushions, the plurality of cushions including the extremely soft cushion significantly displace when a large impact is applied by the hammer coming into contact from the time the hammer touches the stopper to the time it stops. Also, when the hammer comes into contact with the cushion, a cushion compressed feeling is transmitted to a finger tip of a player who feels as if he pushes the finger into sponge, because the jack has not yet come off, thus failing to provide the player with a good hammer striking feeling and stopping feeling, with a resulting damage to a touch feeling. For eliminating such an inconvenience, it is contemplated to employ a hard cushion for the stopper to reduce the amount of displacement thereof. In this event, however, large collision noise occurs when the hammer comes into contact with the hard cushion. In addition, since vibrations associated with the collision are transmitted to a case through the hard cushion and pivotal shaft, noise can be generated.
The present invention has been made to solve the problem mentioned above, and it is an object of the invention to provide a stopper for a keyboard-based musical instrument which is capable of improving a touch feeling and restraining collision noise and other noise by accomplishing a good stop feeling of a pivotable member.
Laid-open Japanese Patent Application No. 6-180583.